This invention relates generally to a control apparatus for an internal combustion engine and particularly to an apparatus for controlling an amount of fuel to be injected into the internal combustion engine when an automotive vehicle is accelerated.
In a conventional internal combustion engine, a fuel injection valve is controlled to open for a predetermined period of time under the condition of normal running of the automotive vehicle in synchronism with a signal detected by means of a crank angle sensor. The fuel injection performed at the normal running of the vehicle is hereinafter referred to as a normal fuel injection. When an automotive vehicle is accelerated, it is desirable to increase the amount of injected fuel as compared with the normal running. For this purpose, the valve is usually controlled to open immediately after the shift from the normal running of the automotive vehicle to the acceleration running is detected. This fuel injection performed during acceleration is hereinafter referred to as a corrective fuel injection. According to a conventional method, however, the corrective fuel injection is sometimes instructed to take place simultaneously with the normal fuel injection since the timing of the corrective fuel injection cannot be controlled. In a case where the instruction signal for the corrective fuel injection is delivered at substantially the same time as that for the normal fuel injection, the amount of fuel injected into the internal combustion engine remains unchanged as compared to the amount of fuel at the normal running. In other words, even though the instruction signal is delivered in order to increase the amount of fuel to be injected, the actual amount of injected fuel into the internal combustion engine sometimes remains unchanged so that the characteristic of acceleration of the automotive vehicle is unsatisfactory.